Abrasive material



Patented Feb. 27, 1940 2,191,803

'UNITED STATES PATENT OFFICE 2,191,803 ABRASIVE m'mami.

Frank D. Oesterle, 'I'eaneck, N. 1., and George Zellar, Harrison, N. 1.,assignors to Western Electric Company, Incorporated, New York, N. Y., acorporation of New York No Drawing. Application July 2, 1938,

' Serial No. 217,216

Claims. (Cl. 51-280) This invention relates to an abrasive material welladapted to produce a uniform effect on and more particularly to anabrasive material curved and irregular surfaces. peculiarly adapted foruse in finishing and're- With these and other objects in view, oneemfinishing ornamental surfaces. bodiment of the invention may comprisea flexipurpose is to produce an ornamental appearance fabric, a bodythereon of flexible and resilient upon a surface by means of coatingsapplied adhesivematerial, e. g., printers roller compound thereto,coatings of paint, varnish, enamel, and of glue and glycerine or softrubber, and abrasive the like, oils, waxes and pastes of many kinds,grains embedded therein.

i0 platings of metal deposited by spraying, electro- Other objects andfeatures of the invention will deposition, chemical deposition, etc.,and others clearly appear from the following detailed dein almostindefinite variety. In a great many scription of embodiments thereof.instances of such procedures, an abrasive medium To make one preferredembodiment of the inmay be used to modify the original surface, thevention, a sheet of ordinary commercial unsurface of some intermediatecoating thereon, or bleached muslin may be used as the base, say a thefinal surface. Purpose of such abrasive may muslin having 5Qx 56 threadsto the inch. For be to remove larger or smaller irregularities, tocorfvenience of use, it is preferred to apply the roughen or matt asurface to give anchorage to adhesive compound to one side only of thisa coating to be applied thereto or to give a decloth base, although bothsides may be coated There is a great variety of procedures whose blebase such as loosely woven or knitted textile 5 sired final mattappearance, "or to smooth or if desired. 20'

polish the surface. A preferred compound for use as the body coat Toeffect such abrasive results, it has long. on the cloth may have thefollowing composition: been well known to use powdered abrasives, sand,

' Per cent emery, carborundum and the like attached to a laminar base,paper, cloth, felt, and such by 355 2352 25 means of common adhesiveslike glue, thus makwater I" about. 10

ing the well known sand paper, emery cloth, carborundum boards, andsuch. These abrasive and for some purposes there may be added to toolssuffer from two familiar defects: they are the above about 3% of linseedoil which acts still generally, and the abrasive grains are rigidly ppae t y to ug the O -P Without 30 secured by the adhesives commonlyemployed to hardening it. To preserve this compound against the backing.Hence, in use, especially on a'ourved attack by mold, or by flies andother insects, or warped surface, in some instances such abrathere mayals be add enough o a Satu ated sive sheets will not conform properly tothe sursolution of copper sulfate in water to give the face and unlessgreat care is exercised the anradwhole a content of about 01% coppersulfate. '35 ing is-uneven. If the abrasive sheet is forced The aboveformula yields a compound giving to curve beyond its naturally limitedability, it aproduct as described below'which is-eminently may tend-tocrack and the grains along the satisfactory for use in roughening andsmoothsharply folded crack may form a saw edge which ilm varnished,japan ename 1 lacquered 40 may do difiicultly reparable damage. Also,the surfaces on sheet metal, especially where the 40 grains are ineffect miniature planing t0o1s mount-, metal sheet has been formed intocurved ored by the rigid adhesive on the backing sheet warped contours.which is itself rendered stiff and rigid by the The above describedcompound is one well absorbed or impregnating adhesive. Hence the knownand commonly obtainable in commerce permissible pressure, to avoid toodeep cutting, under the general name of printer's roller com- 45 i. e.,unsightly scratching, is limited by those of pound", it beingused widelyin the printing art the grains which protrude beyond the average asmaterial for making rollers used in apparatus surface of the grains;and, because a few grains for both direct and offset printing. aretherefore excessive in effect, the majority To apply the compound to thecloth or other 60 must be inefliciently used. base, the compound may bemelted and made 60 An object of the present invention is-to producesuiilciently liquid to form a closely adherent coatan abrasive materialof the'general nature de-. ing onthelcloth without at the same timesatuscribed, which shall be highly emcient in use, f ung- 0;penetratingthe cloth completely. The durable, capable of acting underhigh pressure compoun d may be applied to-the cloth in any withoutproducing objectionable scratching'faiid, convenlentlandsuitablemanner,e. g., by running the cloth over "a roller which dips into the surfaceof the melted compound, or by painting the melted compound or pouring itand spreading it on the cloth. I

The coated cloth may then be allowed to cool, dry and partially hardento still somewhat tacky surface state. Abrasive powder is then appliedto the faintly sticky or tacky surface of the compound and the wholeallowed to cool and harden completely.

A preferred abrasive for use as described above on lacquered metal orthe like, is artificial aluminum oxide, such for example as thatcommercially known by the trade name Aloxite, with a grain size of 120mesh. It may be applied to the tacky adhesive on the cloth by anysuitable and convenient method, e. g., by sprinkling an excess on andshaking, or by passing the coated cloth in front of a dust blowercharged with the abrasive, or'by passing the coated cloth over a rollerlocated in a container filled with the abrasive.

The coated cloth thus loosely charged with abrasive is then preferablypassed between rollers to embed the abrasive firmly in the resilientjelly-like layer of adhesive. Because of the jelly consistency andcharacter of the resilient coating this is not ordinarily to beaccomplished by pressure alone. Preferably the roller against which theuncoated rear face of the cloth runs is cold, even chilled bybeing-hollow and having cold water circulated through it, while thecooperating roller which runs against the abrasive and adhesive coatedside is heated by any suitable and convenient means such as steam. Theheated roller is preferably maintained at such a temperature, dependentamong other factors on the speed of the coated sheet over it and thethickness and intrinsic hardness of the adhesive used, as willsuperficially melt the upper surface of the adhesive to receive andpartially embrace the grains of abrasive, but will not melt the undersurface of the adhesive enough to cause it to soak through the cloth.

The laminar product, after being thus calen-, dared, is then allowed tocool and harden completely and is then ready for use.

Theproduct made as above described, with the glue-glycerine adhesivewhose ingredient proportions are specified above and with 120 meshAloxite as its abrasive, may be compared, "for illustration of itsadvantages, with an ordinary sand paper or emery cloth having plain glueas adhesive and 240 mesh silica sand or emery as abrasive. The sandpaper or emery cloth is stiff. It cannot be bent to any reasonablysnrall radius without the production of saw edged, cracked creases whichare practically certain to produce unsightly scratching, especially ifappliedto concavely curved work. The product of the invention is nearlyas flexible and crumplable as the original cloth. It creases in much thesame manner as the original cloth, in creases or f lds whose edges arenot cracked, and hence not s wtoothed.

Although the product of the invention as described has an abrasive of120 mesh, twice as coarse as the 240 mesh abrasive of the sand paper oremery cloth, it may be applied to and rubbed over a piece of work undereven greater pressure than that which causes the sand paper or emerycloth described to produce objectionable scratches, without any suchobjectionable efiect.

Furthermore, the product of the invention may be used far longer beforebecoming useless resilient adhesive, so that any grain that 'pro-,

jects beyond the average level of the cutting points of the grainsgenerally is relatively easily forced back into the resilient jellyuntil the cutting pressure is fairly evenly divided among 'all .thegrains. In a sand paper, emery cloth or the like made in the ordinaryfashion with a hard adhesive, the grains are rigidly held relatively toeach other andto the backing. Hence any grains protruding beyond theaverage will not yield and retire, but will bear all the burden of thepressure in its neighborhood and so cut abnormally deeply until it hasentered thework far enough to permit nearby grains to begin to cut.

The flexibility of the product of the invention arises primarily fromthe resilient, jelly-like nature of the adhesive. Hence even if thecloth, paper or ,other backing be saturated or coated with the adhesiveon both sides and provided with abrasive on both sides, the flexibilityand softness of the double sided product are but little less than in theone sided product, and are still far greater than with a hard adhesivesuch as glue.

In another method of making the product of the invention, the adhesivecompound may be prepared and melted as before, and when melted maybecharged with the powdered abrasive by stirring the latter into themelted abrasive until evenly distributed therethrough. This mixture ofadhesive and abrasive may then be coated upon a suitable base or backingin any suitable manner.

The invention is not limited to the use of a laminar backing or even toa flexible backing. Thus in the rifles used as sharpening instrumentsfor scythes, sickles and the like in place of whetstones and whichcomprise a rigid core,

e. g., of wood, ordinarily of a. generally oval or elliptical crosssection, and covered with an abraresilient freedom of motion relativelyto each other, material jammed and caught between the grains during oneworking stroke of the rifle are apt to be released and shaken outat thenext.

Where even more resilience is desired, e. g., in working on a corrugatedor other analogous surface, a resilient wad-like or pad-like backing orabrasive charged compou d until saturated through and then cooled andhardened. Such a mass will then present fresh working surfaces wherevertorn or cut apart. For such embodiments of the invention resilientlyspongy masses may be used as a base, e. g., natural sponge, spongerubber, or the like.

While in the adhesive compound described above the glue and glycerineare given in the ratio of two to one (60% to 30%), this proportion ofthese two ingredients may be varied from about one to one to 45%) toabout five to one (75% to 15%) if it be desired to vary' the hardnessand toughness of the compoundwithout taking away its resilientcharacter. So also, the water content, given above as 10%, may be variedrelatively to the total amount of glue and glycerine combined. Theembodiments disclosed are illustrative and may be varied in many wayswithout departing from the spirit and scope of the invention as pointedout in and limited solely by the appended claims.

What is claimed is:

1. In a material for abrasive uses comprising a limply flexible base oftextile threads and a granular abrasive of hard mineral substance, anadhesive compound to secure the abrasive to the base and comprising 45parts to 75 parts dry glue and 45 parts to 15 parts glycerine and 5parts to 15 parts water and 1 part to 5 parts linseed oil.

2. In a material for abrasive uses comprising a limply I flexible baseor textile threads and a granular abrasive of hard mineral substance, anadhesive compound to secure the abrasive to the base and comprising 45parts to 75 parts dry glue and 45 parts to 15 parts glycerine and 5parts to 15 parts water and 1 part to 5 parts linseed oil and ,4 to Apart copper sulfate.

3. In a material for abrasive uses comprising a limply flexible base oftextile threads and a granular abrasive'of hard mineral substance, anadhesive compound to secure the abrasive to the base and comprisingabout parts dry glue and about 30 parts glycerine and about 10 partswater and about 3 parts linseed oil.

4. In a material for abrasive uses comprising a limply flexible base oftextile threads and a granular abrasive of hard mineral substance, anadhesive compound to secure'the abrasive to the base and comprisingabout 60 parts dry glue and about 30 parts glycerine and about 10 partswater and about 3 parts linseed oil and about part copper sulfate.

5. In a material for abrasive uses comprising a limply flexible base oftextile threads and a granular abrasive of hard mineral substance, anadhesive compound to secure the abrasive to the base and comprising 60parts dry glue and 30 parts glycerine and 10 parts water and 3 partslinseed oil.

FRANK D. OESTERLE. GEORGE ZELLAR.

